Improvement in tension devices for sewing-machines



H. BLAND. Tension Device forSewing Machines.

Patented Jan. 19, 1864.

UNITED STATES PATENT OFFIcE.

HENRYv BLAND, on LUToN, ENGLAND.

IMPROVEMENT lN TENSION DEVICES FOR SEWING-MACHINES.

Specification forming part of Letters Patent No. 41,272, dated January19, 1864.

To an whom it may concern Be it known that l, HENRY BLAND, of Luton, inthe county of Bedt'ord, in the United Kingdom of Great Britain andIreland, have invented a new and Improved Tension De- .vice for-Sewing-Machines; and I do hereby declare that the following is a full,clear, and exact description of the same, reference being bad ,to theaccompanying drawings, forming part of this specification, in which-Figure 1 is a side view of the device. Fig. 2 is an end view of thesame. Fig. 3 is a top view of the same, partly in section.

Similar letters of reference indicate corresponding parts in all thefigures.

Hitherto in sewing-machines the operator has had no guide whereby todetermine what amount of tension the thread should have according to thenumber or size.

The object of this invention is to supply this deficiency and to providefor the adj ustment of the tension with certainty; and to this end itconsists in a novel combination of i a perforated screw and a scale,whereby the desired result is accomplished.

To enable others sk lled in the artto make and use my invention, I willproceed to describe its construction and operation.

A represents a block of metal, which may be either made separate andsecured to the training of the sewing-machine in a suitable position orconstitute a portion of the framing itself, having a hole bored throughit for the reception of the plain cylindrical neck of the screw B, whichis titted to turn freely, but not allowed to move longitudinally. Thesaid screw is made with a .head,.b, of such form and size that it may beturned with the thumb and finger, and the block A is fitted with abinding-screw, a, to secure the screw B in any position to which it mayhave been turned. In the extremity of the said screw there is drilled ahole, 0, which comes out on one side.

block A to operate in combination with the scale on the screw-head.

To produce and adjust the tension, the screw B is to be first turned inthe proper direction till the point of the index D arrives at the 0 onthe scale 0, and the thread is then passed on its way from the bobbin tothe needle through the hole 0 and through an eye, 6, in the travelingindex D, and the screw turned in the opposite direction to that firstmentioned, by which means the thread is wound upon the screw between thethreads thereof, and the index l) is moved along the scale 0, upon whichit indicates the number of times the thread is wound upon the screw,while the index dindicates upon the screw-head I) any decimal parts ot'aturn more than any number of whole turns of the thread upon the screw.Now, suppose it to have been ascertained that by winding the thread uponfive threads of the screw the requisite friction is produced to give therequired tension tor a thread of a certain size, I turn the screw farscrew B has been properly adjusted it is secured by the binding-screw a.

Instead of having a traveling index, 1), the scale 0 may be so arrangedrelatively to the screw B that the thread wound upon the screw may serveas its own index.

What I claim as my invention, and desire to secure by Letters Patent,is-

The tension device composed of the screw B and scale 0, combinedsubstantially as and for the purpose herein specified.

HENRY BLAND.

Witnesses:

GEORGE F. WARREN, THOS. BROWN,

-Both of No. 2 George Yard, Lombard Street, I

London.

